The present invention relates to a head drive control apparatus used in a recording/reproducing system for recording/reproducing image information with respect to a disk-shaped recording medium, for example, an optical disk or magnetic disk.
A conventional head drive control apparatus is proposed wherein a head is moved by a driver such as a voice coil motor along a radial direction of a disk, and a mark on a scale provided on a head drive mechanism is read to detect the head position, thereby controlling the head position. In this apparatus, the voice coil motor is driven in a speed control mode until the head reaches a target position. When the head has reached the target position, the voice coil motor is driven in a position control mode. In this mode, the head position is controlled between two adjacent marks on the scale. Therefore, in order to perform servo control of the head position with high precision, the pitch of the marks on the scale must be decreased. However, when the pitch is decreased, the servo range becomes narrowed, resulting in inconvenience.